Web screen printing is a proven production method, yet still misunderstood by the majority of printers in the industry. It is also a versatile and efficient manufacturing technology that screen printers must consider in any production automation or expansion plans. Many printers still do not realize, however, that successful introduction of a higher level of automation requires immediate attention to other support areas--an important thought process that is an integral part of such evaluations. Automation uncovers the weakest link in any manufacturing process immediately, and often ends in disappointment and poor economic performance if not applied correctly.

Screen printers who have this mental awareness can apply web technology with greater success and profitability for short- and medium-length jobs than for those long runs with cut-throat profit margins. The break-even point for run sizes in web screen printing can be as small as 200 or 300 impressions per job, if the web technology is applied correctly. Indeed, web screen printing competes extremely favorably with sheet-fed screen printing and with the emerging digital printing technologies in certain applications.

Obviously, web technology can only be applied when the substrate exhibits enough flexibility to be processed through a web screen-printing or finishing line. These substrates include 1-mil Mylar&reg;, 30-mil polycarbonate, 8-mil polyethylene, various transfer papers, and other materials with thicknesses of up to 0.08 in. (2 mm). An additional competitive edge is web printing's ability to print the back side of the substrate in perfect register to the front--whether the substrate is opaque or translucent. Speed is also an advantage: For example, a 30-in.-wide web press printing at rates of 50-70 ft/min, using either solvent-based or UV inks, would print 125-175 sq ft/ min, with as many colors as the press can print in line. A final benefit is, of course, the ability to select and control ink-deposit thickness--an inherent part of what makes the screen-printing process as a whole so unique. History